The present invention relates to an entrance door for a premises, and more particularly to a door that has one of its faces turned toward the inside of the premises where temperature deviations are limited over the course of a year, and its other face turned toward the outside of said premises, where the temperature deviations are more important.
It is well known that the entrance door face that is turned toward the inside of premises, and characterized by a limited yearly thermal amplitude, undergoes only a limited expansion/contraction in the course of a year. On the other hand, it is also true that the face of that same door that is turned toward the outside of the premises may be subjected to a relatively important expansion/contraction, because of external temperatures that vary, for example, between -10.degree. C. and 40.degree. C. over the year.
This expansion/contraction phenomenon of the external face of an entrance door is further accentuated when that face is made of a metallic material, especially aluminum.
Entrance doors with metal faces generally can be divided into two groups, depending on their structure.
The first group the most commonly used doors, which are made of one or several decorative panels a thermally insulating packing, that are mounted inside a door frame is made of metallic profiles, for example. These panels comprise, on each one of their faces, a metallic facing possibly of aluminum. The thermally insulating packing of these panels is made of polyurethane, for example.
These doors offer the advantage of having reduced expansion/contraction characteristics for their respective external faces, in response to important yearly variations of the outside temperature. Such door, however, come at a rather high cost, and with a less than a perfect aesthetic appearance.
In a second group, there are monoblock doors that usually are made up of a single panel with a thermally insulating packing that is connected so as to form one piece with a frame. This panel and this frame comprise metallic facings that form the faces of the door. Each facing is mounted directly on the above-mentioned frame. The latter is equipped on its respective longitudinal edges, on the one part with means to guide the door when in motion relative to a wall frame, and on the other part, to close it when in a and possibly lock it into closed position.
A major drawback of a door of the monoblock type is found in that this external facing, when it expands/contracts along its periphery because the afore-mentioned yearly thermal temperature variations, exerts stresses on the frame and which becomes deformed, this bringing about difficulties, even possibly the impossibility of a closing of the door.